View
218
Download
1
Category
Tags:
Preview:
Citation preview
TF 8 - Mesh tension / specifications
- Summary on mesh stretching options -
Fabian Kuger1, Esther Ferrer-Ribas2, Mauro Iodice3
1Julius-Maximilians-Universitä̈" t Würzburg (Germany) / CERN, 2 IRFU/SEDI - Saclay (France), 3 Roma Tre (Italy)
April 14th 2014MM Mechanics Meeting - CERN
Mesh stretching in labs or industries?(Options)
Main factors to be considered:
2Mesh TF - reportApril 14, 2014
Logistics Cost Quality
Stretching externally in industries
Stretching externally in industries
Stretching ourselves on production site
Stretching ourselves on production site
One centralized supplier
One centralized supplier
Individual supplier per production siteIndividual supplier per production site
One or two ‘stretching sites’
One or two ‘stretching sites’
Stretching in each production site
Stretching in each production site
Depend strongly on logistics Varies a lot with the supplier
Example calculation will be given, not to be considered as final
Intensively discussed in the weekly meetings.
Today only short summary, More detailed results in backup
A logistics model for each option will be briefly discussed
Overview – logistics structure
3Mesh TF - reportApril 14, 2014
Logistics
Stretching externally in industries
Stretching externally in industriesOne centralized
supplierOne centralized
supplierIndividual supplier per production siteIndividual supplier per production site
Stretching ourselves on production site
Stretching ourselves on production siteOne or two
‘stretching sites’One or two
‘stretching sites’Stretching in each
production siteStretching in each
production site
Centralized stretching site
‘Drift panel’ siteAssembly site
‘Drift panel’ site+ in-lab stretching
Assembly site
centralized supplier
‘Drift panel’ site
mesh delivery (2)
frame return (1)local supplier‘Drift panel’ site
‘regular’ delivery and pick-up by company
Large number of frames, to be reused only one or two times to reduce logistics(-costs).(1000 – 3000 CHF per transport)
Smaller number of frames in two batches, one at site and one at supplier, to be exchanged. (few 100 CHF per transport)
Adds ONE extra logistic step for each (batch of) panel(s). NO extra logistics at all!
4Mesh TF - reportApril 14, 2014
Overview – main cost itemsCosts
Frames: Each stretching in industries solution requires an amount of (reusable) frames to pre-stretch and transport the meshes.
Buying directly from producer saves up ≈ 50% compared to stretching companies.
Exact numbers depend on logistics e.g. 2x 16 frames 8 logistic steps; 2x 8 frames 16 logistic steps
Size(Module)
2.30 x 2.50 m2
(LM1)1.60 x 2.50 m2
(LM2)1.50 x 2.50 m2
(SM1)1.60 x 2.00 m2
(SM2)
frame (CHF/piece) 220 (176€) 193 (154€) 188 (150€) 1.23 (98€)
Stretching Service: Only stretching - no mesh cleaning or frame preparation included! Huge variance dependent on company.
5Mesh TF - reportApril 14, 2014
Example – centralized industrial stretching
Module LM1France
LM2Italy
SM1Greece Russia
SM2Gemany
Frames (kCHF / 64)1. 14.0 12.4 12.0 8.0
Stretching (kCHF/128)2. 6.8 6.8 6.8 6.8
Logistics (kCHF)3. 5 6 10 6
TOTAL 25.8 25.2 28.8 20.8
Mesh fabric not included!
Option 1: Industrial stretching by one supplierHigh number of frames and less reusing will be cheaper than many transports – e.g.: -Buying half of the frames (64) and reusing them once-3 transport steps with full truck (2x company site, 1x site company)
Costs
1.based on Hurtz offer 2. based on Pröll offer 3. Based on 3 transports, e.g. from CERN to ‘drift panel’ site
Option 2: Industrial stretching by local supplier-Lower number of frames sufficient-More logistics steps, but each one much cheaper-BUT: Prices for stretching might differ significantly!
Summary
• Quality highly depends on supplier
Individual qualification and QC necessary with each supplier
• Time for relaxing the mesh on the stretching setup before gluing is very expensive in industries
difficult adjustment to nominal value
• Best Quality delivered so far ±3N/cm over 110x150cm
6Mesh TF - reportApril 14, 2014
Quality
Stretching externally in industries
Stretching externally in industries
Stretching ourselves on production site
Stretching ourselves on production site
• First tests have been performed with satisfying results:
< ±2N/cm over 100x100cm1
< ±1N/cm over 80x100cm2
• Improving our handling of the tools should improve this further
• But: Neither full size, nor gluing process have been tested!
• Workload is reasonably small(< 30 min per mesh)
1 Mechanical setup2 pneumatic setup
company dependent
?
Mesh stretching in labs or industries?(Discussion input)
7Mesh TF - reportApril 14, 2014
Costs Logistics QualityStretching externally
in industriesStretching externally
in industries
Stretching ourselves on production site
Stretching ourselves on production site
Choose & quality one supplier
Choose & quality one supplier
Individual supplier per production siteIndividual supplier per production site
Identify one or two ‘stretching sites’
Identify one or two ‘stretching sites’
Stretching in each production site
Stretching in each production site
+
more suppliers to be qualified
Quality assurance seems feasible.
Doing it our self enables us to include
relaxing time improve quality
20-30 kCHF / construction site
23 – 34 kCHF/ stretching site
+ extra logistics
≤ 23 – 34 kCHF / construction site
e.g. 2 deliveries + 1 frame return
transport solutions by the local companies
No logistic issues
Adds one extra transport step
< 20-30 kCHF/ c.s. (lower frames number,
less transport)
Backup - Industrial stretched meshes
9Mesh TF - reportApril 14, 2014
Quality
MSW meshes - CERN Prototype meshes - LMU
- 7 – 21 N/cm (min-max), 10 N/cm nominal
- Systematic inhomogeneity, huge difference between meshes
- time stability (4 Months) proven: temperature depended deviation observed, otherwise deviation ≤ accuracy of measurement
results in backup slides
- 12 – 17 N/cm (min-max), 13 N/cm nominal
Thanks to Elias & Ralf!
Backup - Self stretching @ GRÜNIG - results
12Mesh TF - reportApril 14, 2014
- ± 2 N/cm (max)
- ‘pre-stretching’ of the mesh is important!
- quality is skill dependent
- larger size might increase difficulties
- ± 1 N/cm (max)
- Individual clamp movement improves homogeneity
- good repeatability
- no concerns about larger size
Quality
Notice: Measurements done on the machine, not after gluing!
Self stretching - summary
Stretching the meshes our self with professional tooling…
… seams quiet easy to learn,
… doesn’t create a huge workload,
(<15 min to install & stretch the mesh, 2 persons required)
… and yields satisfying quality in terms of homogeneity
… but does not come cheap! (23-34kCHF) (renting / reselling the tool tbd…)
Stretching with self made setups (INFN, Class12) …
… is much cheaper
… seems to yield satisfying results as well
… but requires more work and additional R&D
With self stretching, we have the quality of the product in our hands and decrease dependence from industries!
13Mesh TF - reportMarch 3, 2014
Quality
Backup ‘read-to-use’ setups by Grünig
14Mesh TF - reportApril 14, 2014
offers ‘read-to-use’ setups capable to stretch up to 2500x2500 mm2 with ≤ 50 N/cm.
Mechanical tensioning setup (G-Stretch 210) -fast and continuously adoptable to smaller frame sizes -pre-tensioning of the frame -no frame-mesh contact during tensioning-clean room capable
costs: 23.000 CHF
Pneumatic tensioning setup (G-Stretch 215) -individual movement of the clamps compensation of clamping uncertainties possible
costs: 33.800 CHF
Automatic pneumatic tensioning setup (G-Stretch 215A) -very simple to use (click here for demonstration video)-automatic compensation of clamping uncertainties higher homogeneity of the mesh tensioning
costs: 43.000 CHF
Show-room setups can be visited and tested. (Schwarzenburg – 170km, <2h by car from CERN)
17
REUSE OF TRANSFER FRAME WITHOUT GLUE Mesh Transfer: Standard technique•Transfer frames rise from below•Fast-Glue is applied from the top•Reuse of frame: -Easy twice -More times: Cleaning glue on frame surface
Mesh Transfer: Standard technique•Transfer frames rise from below•Fast-Glue is applied from the top•Reuse of frame: -Easy twice -More times: Cleaning glue on frame surface
Double-screwed transfer frame: •Two coupled frames with
surfaces with grooves and
rubber to act as clamps
•One frame is placed below the
stretched mesh
•The companion frame is
positioned from the top with
correponding holes for
screwing
•Screwing in subsequent steps
making one hole per step in
the mesh
•When all screwed, cut the
mesh and transportCan be reused many times
Can be built in parts
-> easy to transport
Double-screwed transfer frame: •Two coupled frames with
surfaces with grooves and
rubber to act as clamps
•One frame is placed below the
stretched mesh
•The companion frame is
positioned from the top with
correponding holes for
screwing
•Screwing in subsequent steps
making one hole per step in
the mesh
•When all screwed, cut the
mesh and transportCan be reused many times
Can be built in parts
-> easy to transport
stretched mesh
Top frame
Bottom frame
Screw
Tests in progress in RomaTre
Recommended